Selective s-triazine herbicides

ABSTRACT

WHERE: R is alkyl with a number of carbon atoms equal to one to five, X is oxygen or sulphur; if X is oxygen and R2 is methyl, then R1 is hydrogen or alkyl with a number of carbon atoms equal to two to four; if X is oxygen and R2 is ethyl, then R1 is hydrogen or alkyl with one to four carbon atoms; if X is sulphur, R1 is hydrogen or alkyl with one to three carbon atoms, then R2 is methyl, ethyl.   Selective s-triazine herbicides for controlling grassy and dicotyledonous weeds in sowings of farm crops, for example, cotton plant, tomatoes, potato, beat, cabbage and other vegetable crops, in which an active agent is 2-(alkoxy-or alkylthio-)-4alkylamino-6-N-alkylhydroxylamino-s-triazine of the general formula

United States Patent [1 1 Volodarskaya et al.

[451 Apr. 16, 1974 1 SELECTIVE S-TRIAZINE HERBICIDES [76] Inventors: Nadezhda Antonovna Volodarskaya,

Turistskaya ulitsa, 8, kv. 117, Moscow; Jury Veniamlnovlch Scheglov, Odintsovsky raion, p/o B. Vyazemy, Institut, 5, kv. 4, Moskovskaya oblast; Irida Alexandrovna Melnlkova, Schelkovskoe shosse, 56/72, kv. 10, Moscow; Nikolai Nikolaevich Melnikov, ulitsa D. Ulyanova, 4, korpus A, kv. 96, Moscow; Jury Alexandrovich Baskakov, ulitsa D. Ulyanova, 4, korpus B, kv, 233, Moscow; Leonid Dmitrievich Stonov, Lavrushensky pereulok l7, kv. 21, Moscow; Ljudmila Alexandrovna Bakumenko, ulitsa Gorkogo, 54, kv. 86, Moscow; Asya Mikhailovna Grabovskaya, Spomy pereulok, 5, Ljubertsky Moskovskoi oblasti; Valentina Grigorievna Kazakova, Beskudnikovsky bulvar, 25, korpus 3, kv. 30, Moscow, all of USSR.

22 Filed: Dec.2, 1970 21 Appl. No.: 94,607

[52] US. Cl. 71/93, 260/2498 [51] Int. Cl A01n 9/22 [58] Field of Search 71/93; 260/2496, 249.8

[56] References Cited UNITED STATES PATENTS 3,505,322 4/1970 Shaw 260/2496 Shaw .1 260/2496 3,364,215 l/1968 Hackmann ct al 260/2498 FOREIGN PATENTS OR APPLICATIONS 1,135,848 12/1956 France 71/93 Primary Examiner-James 0. Thomas, Jr. Attorney, Agent, or Firm-Holman & Stern [5 7 ABSTRACT Selective s-triazine herbicides for controlling grassy and dicotyledonous weeds in sowings of farm crops, for example, cotton plant, tomatoes, potato, beat, cabbage and other vegetable crops, in which an active agent is 2-(alkoxy-or alkylthio-)-4-alky1amino-6-N- a1kylhydroxylaminos-triazine of the general formula 5 Claims, No Drawings SELECTIVE S-TRIAZINE HERBICIDES The present invention relates to methods of weed control through the use of herbicide preparationsselectively destroying grass and dicotyledonous weeds in sowings of farm crop, particularly, cotton plant, tomatoes, potato, beet, cabbage gourd family, millet, parsley, etc.

Widely used herbicides are amino-derivatives of striazine namely, simazine [2-ehloro-4,6-bis- (ethylamino )-s-triazine], atrazine (2-chl0ro-4- ethylamino)-6-isopropylamino-s-triazine), prometrine [2-methylthio-4,6-bis-(isopropylamino)-s1triazine], etc.

These s-triazine herbicides have significant disadvantages.

Simazine and atrazine at soil application keep phytotoxic properties for long periods (up to 2-3 years) and deteriorate sowings of crops sensitive to herbicides and planted some years after the application of these herbicides. In addition, atrazine and prometrine have poor selective properties and can be used only on a limited range of cultivated plants.

The assortment of the triazine herbicides available does not meet the demands of agricultural production.

An object of the present invention is to improve the herbicide properties of the triazine herbicides (selectivity, higher solubility, absence of long-term after-effects and to widen the range of the herbicide assortment.

This object has been attained due to application as selective herbicides of 2-(alkyloxy-or alkylthi-)-4- alkylamino-6-N-alkylhydroxylamino-s-triazines having the general formula:

where R is alkyl with one to five carbon atoms, X is oxygen or sulphur: if X is oxygen and R is methyl, then R is hydrogen,.alkyl with two to four carbon atoms; if X is oxygen and R is ethyl, then R is hydrogen, or alkyl with one to four carbon atoms; if X is sulphur, R is hydrogen or alkyl with two to three carbon atoms, then R is methyl, ethyl.

Examples of the above-said compounds are as follows.

2-methylthio-4-isopropylamino-6-hydroxylamino-striazine (II);

2-methylthio-4-isopropylamino-6-N-methylhydroxylarnino-s-triazine (III);

2-methylthio-4-N-propylamino-6-N-methylhydroxylamino-s-triazine (IV);

2-ethylthio-4-isopropylamino-6-N-isopropylhydroxylamino-s-triazine (V);

2-methoxy-4-isopropylamino-6-hydroxylamino-striazine (VI);

2methoxy-4-ethylamino-6-N-ethylhydroxylamino-striazine (VII);

2-methoxy-4-isopropylamino-6-N-ethylhydroxylamino-s-triazine (VII);

2-methoxy-4-ethylamino-6-N-isopropylhydroxylamino-s-triazine (IX);

2-methoxy-4-isopropylam ino6-N-isopropylhyd roxylamino-s-triazine (X);

2-ethoxy-4-isopropylamino-6-N-n-butylhydroxylamino-s-triazine (XI);

2-methoxy-4-ethylamino-6-N-n-butylhydroxylaminos-triazine (XII);

2-methoxy-4-methylamino-6-N-isopropylhydroxylamino-s-triazine (XIII);

2-ethoxy-4-methylamino--N-n-amylamino-striazine (XIV);

2-methoxy-4-isoamylamino-fi-N-ethylhydroxylamino-s-triazine (XV).

Compounds III; IX and X are the most interesting ones from the proposed group of the compounds.

M They are capable of destroying a. number of resistant grass weeds [for example wild oats (Avena fatua L.), barnyard grass (Echinochloa crusgallis)] and dicotyledonous weeds [for example white goosefoot (Chenopodium album), amaranth, (Amaranthus SPP=), matricary (Matricaria spp. knotweed (Polygonum lapathifolium L.),field pennycress (Thlapsi arventse L.), corn spurry (Spergula arvensis L.),wild-buckweat (Polygonum convolvulus L.), etc]j in sowings of cultivated plants and have the following advantages as compared with the known triazine herbicides (atrazine, propazine, prometrinelz epmpound III a shorter duration of toxic after-effect, good solubility in water at pH 2 8 so that it can be used in the form of water-soluble aminosalts; an original selectivity when used in the vegetation in an effective dose of 2 kg/ha the preparation is harmless for potato, garden radish, sorghum, seed carrot, parsley, celery, mustard, cotton plant; at preemergence application it is harmless for beet, cucumbers, dill; at all terms of cultivation it is harmless for tomatoes, cabbage, or gourd family, for example, melon. It should be noted, that cotton plant is stable to the action of the proposed herbicide, while it is usually very sensitive to the striazine herbicides used nowadays. Tomatoes are also very stable to the action of the proposed herbicides, whereas they can be treated only by a few preparations which are not derivatives of triazine.

In addition to the above-mentioned advantages, compounds IX and X provide for a possibility of postemergence application on a cotton plants field in doses of 1 kg per ha and less, while the presently known cotton preparations, namely, catorane, trephlane, etc. are soileffect herbicides.

The compounds of formula I, which have been first synthesized by the inventors (see Chemistry of Heterocyclic Compounds, (5),697-70l, are heat-resistant compounds capable of being distilled under a high vacuum. Some of them consist of yellowish viscous oils liable to crystallization after a longterm storage, others are white crystalline compounds having a melting point within the range of 50200C. These compounds are quite soluble in low-molecular alcohols, dimethylformamide, acetone, dimethylsulphoxide, diluted alkali and are isolated in a pure state when acidified to pI-I= 7. They are rather soluble in water and feature a poor solubility in hydrocarbons and halohydrocarbons.

The synthesis of the compounds: of formula I is effected by reacting corresponding chloroderivatives of s-triazine with N-alkylhydroxylamines according to the following diagram:

N HCl-HN(R)H N on L J k J 1101 RHN- -Cl NaIlCOa RHN -N N N \R/ where X, R, R, R have the above-stated significance.

The reaction was conducted in a water-dioxane medium at pH 78 in a nitrogen flow with the use of 100 percent, excess of muriatic N-alkylhydroxylamine and a corresponding amount of sodium bicarbonate necessary for neutralization of chlorohydrate and hydrogen chloride released due to the reaction.

Under these conditions the reaction is completed at heating of the mixture up to 5080C during 2 to 3 hours, the produced N-alkylhydroxylamine derivatives of s-triazine having rather a high yield.

The structure of the compounds of formula I has been confirmed by a comparative study of their infrared spectra.

The following example describes the synthesis in detail.

EXAMPLE I The synthesis of 2-methylthio-4-isopropylamino-6-N- methylhydroxylamino-s-triazine 0.1 mole of muriatic N-methylhydroxylamine in 10 ml of water is neutralized in a flow of nitrogen by a solution of 0.1 mole of NaHCO in 25 ml of water at a temperature of 1 0 to 5C. Added simultaneously to the obtained solution is 0.5 mole of 2-methylthio-4- isopropylamino--chlor-s-triazine in 40 ml of dioxane and 0.2 mole of Nal-lCO in 60 ml of water, in which case pH of the mixture is equal to 8. The reaction mixture is stirred during 2 hours at 5560C and during 1 lated in per cent: C 41.89, H 6.59, N 30.55.

The other derivatives of Formula I are produced in a similar way.

The study of the herbicide properties of the compound has been conducted under hothouse conditions. The results of the tests are described in the following Examples and shown in the Tables.

EXAMPLE 2 Hydroxylamine derivatives of s-triazine are dissolved in acetone, a fine layer of soil is treated with the solutions, is carefully mixed and placed into paper cups having a capacity of 300 ml. The sprouting seeds of bean, wheat and garden radish are shown after 24 hours. The above cultures are grown to a 10-day age and are sprayed with solutions of the above compounds in an alcohol-dioxane mixture (3 portions of 75 percent ethyl alcohol 1 portion of dioxane). The doses of the compounds are 5 and 10 kg/ha, the test is repeated twice, the observation is effected within 30 days. The herbicide properties of the compounds are evaulated visually through a three-mark scale. In case of slight damage of the plants the preparation receives a singlescore mark at heavy damage of the plant -2-score mark (-H-) and in the case of complete desctruction of the plant the preparation receives a 3-score mark identification means 1.5 mark, and identification -l-l(+) corresponds to 2.5 marks. The compounds which do not cause any noticeable damage of the plant are evaluated as inactive (0). The phytotoxicity of the tested compounds is compared with that of reference prometrine and atrazine. The results of the tests are given in Table 1.

The experiments have shown that the compounds hour at 80C. During the entire time of the reaction a h in Table 1, when either ppl into nitrogen flow is passed through the mixture. After the Sowlhg pp onto the vegetatlhg P are hlgh' h i h l i i l d down, water i dd d toxicity herbicides close to the standards but have a (one-half by volume) and the solution is acidified with better h y than that t the tf the hydrochloric or acetic acid to pH 7, is saturated with 40 Pounds with a or p P9 0 f l f h common salt and is extracted with benzene or ether (3 VIII) before belhg effectlve h pp l times by 70 ml), the organic layer is dried over MgSO While h compohhds with a thethyl'thlo grout) btflhg is filtered out, and the mother solution is evaporated. suhstahtlahy herblcldes of p h pp The residue is cold-treated (acetone +CO with anhy- By the character of their action the above comdrous (C H O (*5 .ml) and the compound III is filpounds are close to atrazine but the duration of this actered out. An additional amount of compound II] is isotion is different. When applied into a soil, they cause lated by means of multiple precipitation from the ester detention in the growth of the plant during the first 5-7 mother solution with the aid of light petroleum (the days after the appearance of the sproutings, thereafter, boiling point is 40-60C). The total yield of compound they cause shrinkage of the leaf blades after the devel- III is equal to 71 percent, the melting point is 90-lC. opment of chlorosis. if the compounds are applied onto It has been found in per cent: C 41.98, 42.14; H 6.89, the plants, the leaf-blades wilt and dry within the first 6.95; N 30.55, 30.23; C l-1 N 08. It has been calcufew days after the treatment,

" fame I Herbicidejactivity of s-triazine derivatives Herbicide activity of compounds Egg Chemical me 3 7;: Soil application Spraying of plants bean wheat garbean wheat garden den radish radish lll Z-methylthio4-isopropyll0 -H-+ -H-(+) -H"(+) amino-fi-N-methylhydroxyl- 5 O amino-s-triazine VI 2-methoxy-4-isopropylami- 10 +4 1- +-H- +1- H no -hydroxylamino- 5 +-H- s-triazine lV 2-methylthio-4-n-propyl- 10 0 H amino-fi-N-metl'iylhydroxy- 0 U0 0 0 ammo s tnazine 5 Table I-Continued Herbicide activity of s-triazine derivatives Herbicide activity of compounds Com- Dose pound Chemical mle kg/ha SOIl appllcatlon Spraymg of plants bean wheat garbean wheat garden den radish radish ll 2 methylthio-4-isopropyl-amino6- l +-H- 0 -llhydroxylamino-striazine 4-H- 0 0 -l-+- 0 VII Z-methoxy-4-elhylamino-6-ethyll0 -Hl -H-l- 4-H- 0 hydroxylamino-s-triazine 5 -H-(+) 0 VIII 2-meth0x'y-4isopropyl-amino-6-N- I0 +1-1- -H+ 4++ +1-(+) +1- 4-H- ethylhydroxylaminos-triazine 5 -H+ -H+ -H-(+) H+) -lH- Prometrine l0 +1-1- +-l+ -Ht- -H+ -l-H- 5 PH +H- 4-H- -Hl- Fl-h 4-H- Atrazine l0 4-H- -H-l- +1-1- l+lc 5 -i+-l 4-H- H-l- Fl-l 4-H +4-lthe leaves of bean fall off, and chlorosis and drying of the top of the whole plant take place.

As shown in Table 1, compounds 111, VI, V11 and, particularly, compound V111 have the highest herbicide activity.

' EXAMPLE 3 The most active compounds enumerated in Example 2 are applied into soddy podzolic soil to be used for growing testplants thereon or are applied onto IO-day' plants (as described in Example 2) in a dose of 2.5 kg/- ha. The test-plants include bean, garden radish, sunflower, wheat, oats, and maize. The test is repeated five times the observation is effected within days. The herbicide properties of the compounds are evaluated by a decrease in the weight of the green vegetable mass expressed in per cent to the control (Tables 2,3). On

poorly depresses garden radish, wheat and oats (Table' 3,4) but in a dose of 2 kg/ha it can successively be used on potato, tomatoes and cabbage. The above-stated compounds are practically not toxic for maize both when applied into the soil before sowing and when used for the treatment of vegetating plants.

Table 2 Phytotoxicity of s'triazine derivatives applied into soil Decrease weight of green mass in to control Com- Dose pound Chemical name kg/ha garden sun radish bean flowheat oats maize V1 2-methoxy-4-isopropyl- I 0 23" 12 30 29 5" amino-6-hydroxylamino-s- 2 26 76 30 33 59 0 triazine 5 95 90 56 83 82 33" ED 3.3 1.6 4.8 3.0 1.8 8.3 III 2-methylthio-4-isoprol 0 42 26 43 57 21 pylamino46-N-methyl- 2 21 100 60 83 84 18 hydroxylamino-s-triazine 5 79 100 99 97 98 27" ED 3.8 1.5 1.8 1.3 0.8 IV 2-methylthio-4-n l 16" 26 20" l0 Z2" 20 propylamino-G-N-methyl- 2 26 24 27 16 53 20 hydroxylaminms-triazine 5 48 66 63 95 38 ED, 6 6 4.5 4.3 1.9 8.2 ll 2-methylthio-4-isol 1 l 31 3*" 23 28 propylamino fi-hydro- 2 37 19 30 e 0 xylamino-s-triazine 5 97 56 73 96 43 ED 4 2 4.8 3 1.5 6 VIII 2-methoxy-4-isopropyla- 1 42 7 0 75 64 0 mino-6-N-ethylhydroxy- 2 53 69 10 94 82 0 lamino-s-triazine 5 98 98 70 100 98 28 ED, 2 1.8 4 1 1 5 Vll 2-methoxy-4-ethylamil 0 0 0 0 l6 no-6-N-ethylhydroxy- 2 0 0 0 30 36 0 lamino-s-triazine 5 33 26 10 87 16" ED 5 5 5 3.2 2.5 5 Atrazine 1 99 S0 35 98 91 O 2 100 100 100 98 0 5 100 100 I00 100 100 O ED O.5 l 1.2 0.5 0.5 Prometrine 1 5 21" 0 l2 0 9 The decrease in weight of the green mass of plants has not been proved mathematically.

Table 3 Phytotoxicity of s-triazine derivatives sprayed onto plants Decrease in weight of green mass in to control Dose garden sun Pound Chemical kg/ha radish bean flowheat oats maize wer VI 2-methoxy-4-isopropyl- I 30 36 I2 O amino-6-hydroxylamino- 2 43 53 I8 29 26 s-triazine 57 75 43 90 50 0 121) 3.5 1.8 6.4 3 5.4 0 II 2-methyIthi0-4-isol 64 47 32 O propylamino-fi-hydro- 2 29 76 82 49 7l 0 xylamine-a-triazine 5 59 92 8| 78 0 ED 4.5 l I l 2.2 1.8 VIII 2-methoxy-4-i1to I I9 I5" II" 4" propyI-aminO-(a-N- 2 56 27-" 46 ethylhydroxylumino- 5 64 67 60 54 27 6 s-triazine ED 3 2 3.8 4.4 5 5 VI 2-methoxy-4ethylami I 0 0 0 6 0 0 no-6-N-ethylhydroxy- 2 10" 26 7 I5" 0 0 lamino-s-Iriazine 5 29" 30 29 I7 0 0 E1) 5 5 5 5 III 2-methylthic-4-isopropyl- I 20" 88 0 33 I3" amino-6-N-methylhyd- 2 55 84 ll" l6 roxyl-amino-s-tria- 5 73 61 I00 61 81 21" zine ED 2.4 0.8 0.5 3.5 2 5 Atrazine I I00 90 I00 75 96 0 2 I00 I00 I00 97 I00 0 5 I00 97 I00 I00 I00 13 E13,, 0.5 0.5 0.5 0.4 0.5 5 Prometrine I 90 74 96 63 81 0 2 97 9I I00 83 I00 24" 5 I00 I00 I00 92 I00 43 ED 0.5 0.5 0.5 0.7 0.5 5

*" A reduction in weight of the green mass of the plants has not been proved mathematically.

Table 4 EXAMPLE 4 Phytotoxicity of s-triazine derivatives Compound ED, in kg per ha (by reduction of weight or green mass of plants in m comm) seeds or vegetatlve organs (rootstocks) to l0 or 20 day age and are treated with a water suspenslon of com- 8 24 been wheat mile pounds III and VI in doses of 2 and 5 kg/ha. Prometrine I S I a and atrazme are used as a standard. After 30 days the Soil application of preparations herbicide properties of the compounds are evaluated v] 33 "6 M 30 L8 83 by the reductlon 1n the weight of the green mass on the v111 3.1; 1.5 1.8 1.3 0.8 cult1vated plants (Table 6) and by observing the weeds IV 6 6 4.5 4.3 L9 8.2 (Table 7 11 4 2 4.8 3 1.5 6 W11 2 L8 4 1 1 5 As seen from the Tables, compounds III and VI fea- Xg 5 5 2 2 5 ture an original selectivity of the herbicide action ad-' pmm'emne Lg 3 5 vantageous as compared with the standard.

p y preparfllwns 0M0 Plants The following cultivated plants are stable to the acv1 3.5 1.8 6.4 3.0 5.4 f d m d f 2 k /h n 45 1 H 2.2 L8 t1on o compoun 1n a ose 0 g a. pea, sovv111 3 2 3.8 44 5 5 a bean, cucumbers, melon, pumpkin, mlllet, maize, cor1- v11 5 5 5 5 m 2'4 M 05 35 2 5 ander, carrot, lettu ce, potato, tomatoes, in a dose of 5 Atrazine 0.5 05 05 0.4 0.5 5 kg/ha: pumpkin, millet, cabbage, maize, carrot, potato. Pwmemne 05 05 M M 5 Pumpkin, lettuce, millet and carrot are stable to com- 7 Table 5 Phytotoxicity of compound III as compared with prometrine and atrazine in the process of treatment of vegetating plants Prepa- Do- Reduction of weight of green mass in with reference rations ses, to control kg/ha tomatoes cabbage Sorsoyflax carpo seedbeet pea 2 seedcubuckghum rot tato real lings real Iings cumwheat bean lea (6 Iea- Iea- (6 Ieabers ves ves) ves ves Cultivated plants (21 species) and weeds (22 species) are grown in paper cups and clay flower-pots from j Table 5-Continued Phytotoxicity of compound III as compared with prometrine and atrazine in the process of treatment of vegetating plants Prepa- Do- Reduction of weight of green mass in with reference rations ses, to control kg/ha tomatoes cabbage Sorsoyflax carpo- 2 seedbeet pea 2 seedeubuckghum rot tato real lings real lings cum wheat bean lea- (6 lealea- (6 leabers ves ves) ves ves 5 as 100 92 66 100 0 100 56 so 0 100 100 Atra- 2 99 56 42 20 94 100 87 95 100 100 zine s I00 92 so 100 100 100 as 100 100 100 Pro- 2 100 100 100 100 metrI- 100 I00 I00 I00 ne pound VI in a dose of 5 kg/ha, wh1le atrazine taken in EXAMPLE 5 the above doses suppreses all these cultures, except for Compound III in the form of solution in acetone eimillet and maize, for 40-IO0%, whereas prometrine ther is applied into soil prior to planting out seedlings does not make damage only to pea, pumpkin and maizof white-head cabbage and tomatoes and to seeding of e. The efficiency of compounds III and VI in the action some species of weeds or the cabbage and tomatoes pl- 011 weeds are comparable with the standards for the ants are treated with a solution of compound "I in an most of the testedspecies of plants (Table 7). alcohol-dioxane mixture (noted in Example 2) 2 weeks W WN QRLAN QQEQE. PREEMERGENCE SOIL APPLICATIQN Reduction in weight of green mass of plants in percent with reference to control Cabbage Tomatoes Seedseed 3rd lings lings devel- 4-5 6 devel- Garden Dose, oped real oped Buck Soy- Cucum- Pump- Mil- Cori- Car- Letstraw- Po- Red Compound kg/ha leaf leaves leaves wheat Pea bean Flack bers Melon kin let ender rot tuce berry tato beet VI 2 I5 13 9 20 26 21 3O 0 0 44 0 0 62 5 28 58 23 23 46 72 SI 1] 7 78 9 52 93 Ill 2 0 13 "3 41 l0 0 0 0 18 0 0 10 5 28 100 27 20 79 78 X 14 19 27 0 93 Atrazine 2 10o 14 51 7s 89 100 41 x 2 22 59 86 100 5 100 8l I00 I00 100 3] 78 95 I00 100 Prometrine 2 100 0 36 55 ll 40 0 "32 53 90 5 100 20 57 93 74 67 X 15 0 45 65 100 N Reduction in weight of the green mass of the plantshas not been proved m ath ematicallv.

Table 7 Herbicide activity of compound III as compared with prometrine in case of postemergence application on weeds (in dose of 2 kg/ha) Item Name of weeds Phase of No. development in moment Compound 1 of treat- III Ifrometrine ment 1. Greater plantain 2-3 developed (Plantago major) leaves r 2. White goosefoot 2-4 developed -|H- (Chenopodium album) leaves blooming H-l- 4-H 3. Knotweed (Polygonum 3 developed 4-H- lapathifolium L.) leaves 4. Wild buckweed (Polygonum 5-6 developed PH- convolvulus L.) leaves 5. Knotgrass (Polygonum 6-8 developed H(+) ll-(+) aviculare L.) leaves 6. Sheep sorrel (Rumex 3-4 developed 4-H H-lacetosella L.) leaves Sheep sorrel (Rumex From rootstock 0 acetosella L.) -4 developed e es.

Table 7 -Cgn tinued Herbicide activity of compound III as compared with prometrine in case of postemergence application on weeds (in dose of 2 kg/ha) Item Name of weeds Phase of No. development in moment Compound of treat- I" Prometrine men! 7. Field pennycress 2-4 developed H-(+) l-H- (Thlaspi arvense L.) leaves 8. Thom-apple (Dature 2 developed lll -ll+ stramonium L.) leaves 9. Black hendane 2-3 developed -H+ -Hl (Hyoscyamus niger L.) leaves 10. UirlTnfilllTfiIVflrTiscum 3-4 developed H+ ll| nigrum L.) leaves I 1. Campion (Silene latifolia 5-6 developed H|- -lll- Rende et Brit) leaves 12. Gem spurry (Spergula 2 whorls of6 lil lllarvensis L.) leaves each 13. Wild oats (Avena fatua) 2-nd leaf H- ll-(+) 14. Common yarrow (Achillia 3-4 developed ll+ +H- millefolium L.) leaves 15. Cocklebur (Xanthium 3-4 developed -l+(+) ll+ spinosum L.) leaves l6. Matricary (Matricaria 8-10 developed matricarioidis) leaves, beginning of blooming 17. Creeping thistle (Cirsium From rootstock arvense Scop.) 3-4 developed leaves l8. Field sow thistle From rootstock 0 (Sonchus arvensis L.) 3-4 developed leaves 19. Mugwort (Artemisia 4-5 developed +l-+ l++ vulgaris L.) leaves 20. Purple deadnettle (Lamium Blooming llllll purpureum L.) 21. Field mint (Meutha 4-6 developed ll(+) +l-(+) arvensis L.) leaves 22. Red hemp-nettle 4-6 developed lll -|ll- (Galeopsis ladanum) le ves after the planting, while the weeds are treated 2 weeks of herbicide reducing the weight of the green mass of after the seeding. A month after the beginning of the the weeds by 80 percent). Prometrine and semerone, test the preparation index ED is determined for each 40 which is used in practice for cabbage, were employed culture (a dose of herbicide reducing the weight of the as standards. green mass of the culture for 20 percent) and prepara- The test has shown (Table 8) that compound III is tion index ED for each species of the weeds (a dose less toxic for cabbage that semerone.

TABLE 8 Indices ED for cultures and ED for weeds of 2-methylthio-4-isopropylamino-fi-N-methyl hydroxylamino-s-triazine (compound lll) Item Name of No. of ED ED ED ED No. culture compound of culof or weed or name ture weed of preparation Treatment of vegetating plants grass Prometrine W 0.56 0.55-0.57

TABLE 8 Continued lndices El) for cultures and ED for weeds of 2-methy1thio-4-isopropylamirio-o-N-methyl hydroxylamino-s-triazihe (compound 111) Item Name of No.0f ED ED ED ED No. culture compound of of no "i no:

or weed or name ture weed of preparation T6. air-hymn" grass lll 1.43 1.36-1.50 11. Barnyard grass Serherone 2.5 2.43-2.58 12. Wild camomile lll 2 1.9-2.13 13. Wild j camomile Prometrine 0.34 0.33-0.35

14. Wild carnomile Senierone 0.15 0.14-0.16 15. White goosefoot Prometrine 0.21 0.20-0.22 16. White goosefoot Somerone 0.10 0.08-0.13 17. White goosefoot lll 0.80 0.76-0.86 18. Cabbage Prometrine 2.2 2.17-

19. Cabbage 111 10.1 20. Cabbage Semro'ne 2.7 2.6-

2.8 21. Tomatoes lll 10.0

Soil application of herbicides 22. Wild oats Prometrine 1.45 1.37-1.55 23. Wild oats lll 1.24 1.15-1.35 24. Wild oats sememne 0.49 0.46-0.52 25. Wild oats Senierone 0.9 0.86-0.96 26. Couch grass Fromctrine 0.52 0.51-0.53 27. Couch grass 1.45 1.40-1.52 28. Amaranth Seinerone 1.1 1.01-1.23 29. Amaranth Prometrine 1.28 1.19-1.42 30. Amaranth 111 2.18 2.1-2.3 31. Field P n cress Ill 4.7 4 5,4 32. Field P ycress Prometrine 0.82 0 8-0.84 33. Cabbage 111 14.0 34. Cabbage Semerone 2.8 2.72-2.87 35. Cabbage Prometrine 0.78 0.71-0.86 i 36. Tomatoes lll 3.4 3.93-3.53

ED of semerone fol spraying of the plants is et iu al EE l alst s 5' '7 i 1 rome to 2.7 kg/ha, 0f cornpound llI 10.1 kg/ha. When the (m 5 herblcldes are applied into SO11 prior to introducing the a 'i i grass Z-g H r 1 atricary seedl ngs, ED of semerone for cabbage is equal to 2.8 whim gdosefoot HA kg/ha and of compound Ill 14 kg/ha. Semerone 1s F l l t' i th sel ct'v't indeii ED of wild oats and wheat grass is m w 7 g rgplaz ed 1 31:30? 10 lig'lha de pi' ss'ing the weight of green mass of these plants By using indlces ED of the preparation for cultures by 3! and ED for weeda the selectivity indices of the herbicides are determined. On spraying the plants, the selectivity indices of compound 111 are high considerably higher than 2 (Table 9).

Semerone depresses dicotyledonous weeds more in- TABLE 9 tensiv'ely than monocotyledonous weeds. Its selectivity index for cabbage relative to monocotydonous weeds Scleclivily i i lw 97 'P "9 is not high. The same may be said about prometrine. 6-N-methy1hydroxylamino-s trlazme as compared with k U 1 L r h h. promeirine and semerone in spraying the plants Compound I is advantageous m that n as 3 lg lectivity index for cabbage ahd tomatoes relative to Cultures weeds cong gilii barnyard grass. inatricary and white goosefoot, which Hamming semen, are often basic infestants of vegetable crops.

i i 0 2 Thus, compound III is a highly selective herbicide on White-head Wheat grass 2. cabbage Dmping Name 53 cabbage and tomatoes when spraying the plants 2 l g Wild cats I 2.5 0.2 0.7 weeks after planting the seedlings. ThlS compound, f ggggf Z 3-; 1 h, when applied into soil prior to the seedlings (Table 10 White goosel'oot 11.2 10.0 27.0 also has good selectivity indices relative to weeds.

15 TABLEVIO Selectivity indices of compound III applied into soil prior to sowing (planting) of cultures in comparison with selectivity indices of prol6 tions. They feature high herbicide activity both at reemergence application and at treatment of vegetating plants.

EXAMPLE 8 In a hothouse the Kochs dishes filled with earth are used for sowing 20-30 seeds of cultivated plants and weeds, thereafter, the soil surface is sprayed with a water suspension of compound IX taken in doses 1, 2.5 and kg/ha. The procedure is repeated three times. 28 days after the appearance of the sprouting of the plants the weight of their green mass is calculated. During the vegetation other plants are treated in the phase of development of 23 leaves, the calculation being pro- AS shown in Table 10, compound III is a highly sele vided 28 days after the treatment. In doses of 2.5 and tive herbicide on cabbage also when applied into soil kg/ha compound IX has shown total c'i activprior to the Seedlings 1ty (Table 12). However, cotton plant un er preemergence application of the herbicide in these doses was EXAMPLE 6 depressed only by 8 and 61 percent, while millet under Compound III in the form of water suspension of 40 Postamergence application of the hefblclde was percent wetting powder is applied into soddy podzolic Pressed y and 26 P f respectlvely- In do'se loamy soil in a dose of 4 kg/ha on a trial plot. The area of 1 kg/ha the Preparation both modes of apphcatlon of the plot is equal to 5 m the test is repeated five timp ly destroyed mustard, carrot, g es. Prometrine was used as a standard (as a preparation 25 beat, While Oats and barley were destroyed y 50-75 of s-tgazige hergicides quicgkly delcomposinfg iln a soil). g t f g cottton Plant pp l il :1; l t w:: 30, an 100 ays a tert e app ication o t e prepaer 101 e Preemergence PP ml 6 rations, average soil samples were taken from the work- Stable thereto at Postemergence application It is ing plot and residual amo nts of th re r ti i th known that cotton plant is very sensitive to atrazine and samples were determined by the method of bioindicas A s] li yng' h tion. arnyar grass, amaran no wee sa us an The experiments have shown that the inactivation of camomile were completely destroyed by the preparacompound III during a period of 100 days is within 76 i n appli in the lowest test doses g/h under the per;:ent,2while that of prometrine during the same peprgmerghence Zizonltjlitlions (Tz6tb1l?bl3).1h d l rio is 4 ,percent. -met oxy- -et y ammouty y roxy amino-s- AMPLE 7 triazine had a similar activity. The primary evaluation of a number of hydroxylam- EXAMPLE 9 n e der1v at 1 v e s of formula I IS effected by a somewhat modified method described in Example 2, among other In slmllaf tests compound X adose of kg/ha things, on the following test-objects: oats, millet, bean, dPtf f harmless for P d f ;l mustard. The treatment is effected by the preparations con 1 0 Pre e mergence PP 163 an ell in the form of a water suspension of 40-per cent wetting ai condltlons of Postemergence appllcatlon powders or 40-per cent emulsion concentrate. The ab 6 12 doses f the compounds are taken equal to 10 The preparation had a total herbicide effect on weeds The treatment is carried out both prior to appearance in a dose of 1 kg/ha at P f application (Table of sproutings and during the vegetation of the plants f i y' p f y y y into the phase of 2 or 3 leaves and further, as described y r zm ac imilarly. in Example 2. The results of the herbicide action are expressed in per cent relative to control (Table 11).

The trials have shown that 2-methoxy-4-ethylamino- N N 6-N-isopropylhydroxylamino-s-triazine (IX) and 2- I methoxy-4-isopropylamino-o-N-isopropylhydroxk NJ-NHR ylamino-s-triazine (X) are the most active preparai TABLE 1 l Reduction of weight of green mass of plants in per cent, relative to control Com- Dose pound Chemical title in preemergence treatment in kg-ha application vegetation oats milbean mus oats milbean muslet tard let tard IX 2-methoxy-4 ethylamino-tS-N-isopropylhydroxylamino-striazine I0 97 100 93 I00 100 100 95 X 2-methoxy-4-isopropylamin0-6-N-is0- ro lh drox lam'no- -uiii zinle y l 10 9| 100 84 I00 100 I00 95 100 TABLE 12 D Reduction of weight of green mass of plants in percent relative to control use in kg/Ea Preemergence application Application during vegetation X. active Mll- Bar- Mus- Car Cab- Cot- Mil- Bar- Mus- Car- Cab- Cot- Compound agent Oats let ley Bean turd Flax rot bage Beet ton Oats let ley Bean tard Flax rot bage Beat ton 100 100 100 100 100 100 100 100 100 ET 9s 26 100 100 100 100 100 100 100 95 2.5 100 90 100 100 100 100 100 100 100 8 84 100 100 100 100 100 100 100 85 1.0 75 50 78 78 100 68 100 100 100 9 77 34 87 100 100 100 100 100 51 5 100 100 100 100 100 100 100 100 100 33 90 69 38 95 100 89 83 100 100 64 2.5 94 71 92 100 100 100 10,0 100 100 10 59 2 22 77 I00 34 38 84 93 33 1.0 73 41 78 65 98 100 67 100 I00 0 54 0 22 43 49 61 59 93 0 TABLE 13 Compound Reduction of weight of green mass of plants in relative to control Dose in kglha Preemergence application Application during vegetation Wild Barny- Knot amasaltmatwild Barny- Knotamasaltmatrioats ard weed ranth bush ricaoats ard weed ranth bush cary grass ry grass [X 5.0 100 100 100 100 100 100 100 89 100 97 100 100 2.5 100 98 100 100 100 100 93 61 Y 98 93 100 100 1.0 87 91 91 100 100 '100 9 5 58 8 77 84 100 5 X 5.0 95 98 100 100 100 100 100 68 100 72 88 97 2.5 90 98 100 100 100 100 47 52 62 44 85 97 1.0 75 68 93 82 100 100 50 12 0 30 66 We claim: 30 R is alkyl of one to two carbon atoms; and

l. A method of weed control which comprises applying to the area to be protected 21 herbicidally effective amount of a compound of the formula ith wherein R is alkyl of one to five carbon atoms;

R is selected from the group consisting of hydrogen and alkyl of one to four carbon atoms;

2-methylthio-4-isopropy]amino-6-N-methylhydrox- X is selected from the group consisting of oxygen and sulfur.

2. A method of claim 1, in which said compound is 40 2-methoxy-4-isopropylamino-6-N isopropylhydroxylamino-s-triazine.

5. A method of claim 1, in which said compound is applied at a rate of from about 1 to about 2 kglha. 

2. A method of claim 1, in which said compound is 2-methylthio-4-isopropylamino-6-N-methylhydroxylamino-s-triazine.
 3. A method of claim 1, in which said compound is 2-methoxy-4-ethlamino-6-N-isopropylhydroxylamino-s-triazine.
 4. A method of claim 1, in which said compound is 2-methoxy-4-isopropylamino-6-N-isopropylhydroxylamino-s-triazine.
 5. A method of claim 1, in which said compound is applied at a rate of from about 1 to about 2 kg/ha. 